Diodes Incorporated Introduces a New Controller for P-Channel Enhancement Mode MOSFETs

Diodes Incorporated has engineered its new DZDH0401DW to provide greater power efficiency in a simple, compact design. The controller is cased in an SOT63 package measuring just 2.1 x 2.15 x 1 mm, and can reliably block reverse current up to 40 V.

A typical DZDH0401DW configuration. Image used courtesy of Diodes Incorporated

 

As illustrated in the schematic, the DZDH0401DW enables a streamlined system. Here, it is accompanied by a single MOSFET and just two resistors, making it suitable for space-constrained designs. 

 

Basic Operation, In Depth

The DZDH0401DW operates as a differential amplifier, comparing VOUT to VIN. It is designed to control a P-channel enhancement mode FET, a type of FET that is normally open — no conduction.

If in typical configuration the measured differential between VIN and VOUT is greater than ~34 mV, the controller will drive a reduction in voltage across RBIAS and the P-channel FET will turn on, conducting with minimal current losses. If the differential falls below that threshold, the controller will instead drive a voltage rise across VBIAS, and the FET will turn off. This effectively isolates VIN from VOUT.

 

Improvement over Diode-based Solutions

Diode rectifiers typically feature a voltage drop of 0.55 volts. At 3 A, power dissipation is 0.55 V x 3 A = 1.65 watts. The DZDH0401DW companion FET touted by Diodes Incorporated, the DMP4047LFDE, has an RDS(ON) of 33 mΩ. At 3 A, I2R is 3 x 3 x .033, or 0.297 W.

 

The DMP4047LFDE. Image used courtesy of Digi-Key

 

At 3 amps of forward power, that difference represents significant energy savings. Crucially, it also indicates that less waste heat will be generated. 

 

Major Specifications of the DZDH0401DW

Absolute Maximums

• Max input voltage: 40 V 
• Peak bias current: -300 mA 
• Max reverse voltage protection: 50 V 

Thermal Characteristics

• Power dissipation: 300 mW
• Thermal resistance, junction to ambient: 424 ℃/W
• Thermal resistance, junction to case: 111 ℃/W
   

Derating

Maximum power dissipation persists up to 25 ℃. Beyond that point, power dissipation decreases linearly to zero at 150 ℃.

 

Applications

• Battery discharge protection
• High-side disconnect switches
• OR-ing rectifiers used in data centers' hot-swappable and N+1 redundancy power supplies 
• Battery discharge protection 
• Cordless power tools
• Emergency lighting systems 
   

Physical Considerations

• The DZDH0401DW operates over a temperature range of -65 to +150℃
• Moisture sensitivity at level 1 as per J-STD-020 
• UL flammability classification rating is 94 V-0 
   

Regulations 

Diodes Incorporated can supply the DZDH0401DW in versions qualified to AEC-Q100/101/200, and that are PPAP-capable, if needed. The company can also manufacture the device in IATF 16949-certified facilities.

 

Environmental Notes 

• Lead-free & fully RoHS-compliant
• Halogen and antimony-free 

 

Feature image used courtesy of Diodes Incorporated